Electric machines often use brushes to contact a rotating commutator and conduct electric power to a winding. Brushes are wear items in electric machines which employ them and generally function well until the brushes are worn beyond their service life. At the end of the service life of one or more brushes in a particular machine may fail to function. Because a machine that does not function impacts other operations, it is desirable to avoid a failure of the machine. Maintenance of wear items can certainly avoid failures but often the employment of a maintenance schedule entails the replacement of parts of the electric machine before its actual service life is over. In part this is because each electric machine and its unique environment of operation will have a distinct service life. Early replacement of parts or of the electric machine increases costs. Unfortunately heretofore there has been no mechanism or method to monitor the brushes actual life such that reliable replacement at an actual needed interval could be accomplished leaving the industry with scheduled maintenance (and inherent added cost) as the only option. The industry then would be receptive to reliable alternatives.